org.jboss.netty.buffer.EmptyChannelBuffer

All Implemented Interfaces:: Comparable<ChannelBuffer>, ChannelBuffer

public class EmptyChannelBuffer extends BigEndianHeapChannelBuffer

An immutable empty buffer implementation. Typically used as a singleton via ChannelBuffers.EMPTY_BUFFER and returned by ChannelBuffers.buffer(int) etc when an empty buffer is requested.

Note: For backwards compatibility, this class extends BigEndianHeapChannelBuffer. However, it never makes any writes to the reader and writer indices, which avoids contention when the singleton instance is used concurrently.

Field Summary

Fields

Modifier and Type

Field

Description

private static final byte[]

BUFFER

Fields inherited from class org.jboss.netty.buffer.HeapChannelBuffer
array
Constructor Summary

Constructors

Constructor

Description

EmptyChannelBuffer()
Method Summary

Modifier and Type

Method

Description

protected void

checkReadableBytes(int length)

Throws an IndexOutOfBoundsException the length is not 0.

private void

checkWritableBytes(int length)

Throws an IndexOutOfBoundsException the length is not 0.

void

clear()

Sets the readerIndex and writerIndex of this buffer to 0.

void

discardReadBytes()

Discards the bytes between the 0th index and readerIndex.

void

markReaderIndex()

Marks the current readerIndex in this buffer.

void

markWriterIndex()

Marks the current writerIndex in this buffer.

void

readBytes(byte[] dst)

Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= dst.length).

void

readBytes(byte[] dst, int dstIndex, int length)

Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).

ChannelBuffer

readBytes(int length)

Transfers this buffer's data to a newly created buffer starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).

void

readBytes(OutputStream out, int length)

Transfers this buffer's data to the specified stream starting at the current readerIndex.

void

readBytes(ByteBuffer dst)

Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination's position reaches its limit, and increases the readerIndex by the number of the transferred bytes.

int

readBytes(GatheringByteChannel out, int length)

Transfers this buffer's data to the specified stream starting at the current readerIndex.

void

readBytes(ChannelBuffer dst)

Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination becomes non-writable, and increases the readerIndex by the number of the transferred bytes.

void

readBytes(ChannelBuffer dst, int length)

Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).

void

readBytes(ChannelBuffer dst, int dstIndex, int length)

Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).

void

readerIndex(int readerIndex)

Sets the readerIndex of this buffer.

ChannelBuffer

readSlice(int length)

Returns a new slice of this buffer's sub-region starting at the current readerIndex and increases the readerIndex by the size of the new slice (= length).

void

resetReaderIndex()

Repositions the current readerIndex to the marked readerIndex in this buffer.

void

resetWriterIndex()

Repositions the current writerIndex to the marked writerIndex in this buffer.

void

setIndex(int readerIndex, int writerIndex)

Sets the readerIndex and writerIndex of this buffer in one shot.

void

skipBytes(int length)

Increases the current readerIndex by the specified length in this buffer.

void

writeBytes(byte[] src, int srcIndex, int length)

Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).

int

writeBytes(InputStream in, int length)

Transfers the content of the specified stream to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.

void

writeBytes(ByteBuffer src)

Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer's position reaches its limit, and increases the writerIndex by the number of the transferred bytes.

int

writeBytes(ScatteringByteChannel in, int length)

Transfers the content of the specified channel to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.

void

writeBytes(ChannelBuffer src, int length)

Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).

void

writeBytes(ChannelBuffer src, int srcIndex, int length)

Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).

void

writerIndex(int writerIndex)

Sets the writerIndex of this buffer.

void

writeZero(int length)

Fills this buffer with NUL (0x00) starting at the current writerIndex and increases the writerIndex by the specified length.

Methods inherited from class org.jboss.netty.buffer.BigEndianHeapChannelBuffer
copy, duplicate, factory, getInt, getLong, getShort, getUnsignedMedium, order, setInt, setLong, setMedium, setShort

Methods inherited from class org.jboss.netty.buffer.HeapChannelBuffer
array, arrayOffset, capacity, getByte, getBytes, getBytes, getBytes, getBytes, getBytes, hasArray, isDirect, setByte, setBytes, setBytes, setBytes, setBytes, setBytes, slice, toByteBuffer

Methods inherited from class org.jboss.netty.buffer.AbstractChannelBuffer
bytesBefore, bytesBefore, bytesBefore, bytesBefore, bytesBefore, bytesBefore, compareTo, copy, ensureWritableBytes, equals, getBytes, getBytes, getBytes, getChar, getDouble, getFloat, getMedium, getUnsignedByte, getUnsignedInt, getUnsignedShort, hashCode, indexOf, indexOf, readable, readableBytes, readByte, readChar, readDouble, readerIndex, readFloat, readInt, readLong, readMedium, readShort, readUnsignedByte, readUnsignedInt, readUnsignedMedium, readUnsignedShort, setBytes, setBytes, setBytes, setChar, setDouble, setFloat, setZero, slice, toByteBuffer, toByteBuffers, toByteBuffers, toString, toString, toString, writable, writableBytes, writeByte, writeBytes, writeBytes, writeChar, writeDouble, writeFloat, writeInt, writeLong, writeMedium, writerIndex, writeShort

Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Details
- BUFFER
  
  private static final byte[] BUFFER
Constructor Details
- EmptyChannelBuffer
  
  EmptyChannelBuffer()
Method Details
- clear
  
  public void clear()
  
  Description copied from interface: ChannelBuffer
  
  Sets the readerIndex and writerIndex of this buffer to 0. This method is identical to setIndex(0, 0).
  Please note that the behavior of this method is different from that of NIO buffer, which sets the limit to the capacity of the buffer.
  
  Specified by:
  
  clear in interface ChannelBuffer
  
  Overrides:
  
  clear in class AbstractChannelBuffer
- readerIndex
  
  public void readerIndex(int readerIndex)
  
  Description copied from interface: ChannelBuffer
  
  Sets the readerIndex of this buffer.
  
  Specified by:
  
  readerIndex in interface ChannelBuffer
  
  Overrides:
  
  readerIndex in class AbstractChannelBuffer
- writerIndex
  
  public void writerIndex(int writerIndex)
  
  Description copied from interface: ChannelBuffer
  
  Sets the writerIndex of this buffer.
  
  Specified by:
  
  writerIndex in interface ChannelBuffer
  
  Overrides:
  
  writerIndex in class AbstractChannelBuffer
- setIndex
  
  public void setIndex(int readerIndex, int writerIndex)
  
  Description copied from interface: ChannelBuffer
  Sets the readerIndex and writerIndex of this buffer in one shot. This method is useful when you have to worry about the invocation order of ChannelBuffer.readerIndex(int) and ChannelBuffer.writerIndex(int) methods. For example, the following code will fail:
  // Create a buffer whose readerIndex, writerIndex and capacity are // 0, 0 and 8 respectively. ChannelBuffer buf = ChannelBuffers.buffer(8); // IndexOutOfBoundsException is thrown because the specified // readerIndex (2) cannot be greater than the current writerIndex (0). buf.readerIndex(2); buf.writerIndex(4);
  The following code will also fail:
  // Create a buffer whose readerIndex, writerIndex and capacity are // 0, 8 and 8 respectively. ChannelBuffer buf = ChannelBuffers.wrappedBuffer(new byte[8]); // readerIndex becomes 8. buf.readLong(); // IndexOutOfBoundsException is thrown because the specified // writerIndex (4) cannot be less than the current readerIndex (8). buf.writerIndex(4); buf.readerIndex(2);
  By contrast, this method guarantees that it never throws an IndexOutOfBoundsException as long as the specified indexes meet basic constraints, regardless what the current index values of the buffer are:
  // No matter what the current state of the buffer is, the following // call always succeeds as long as the capacity of the buffer is not // less than 4. buf.setIndex(2, 4);
  Specified by:
  
  setIndex in interface ChannelBuffer
  
  Overrides:
  
  setIndex in class AbstractChannelBuffer
- markReaderIndex
  
  public void markReaderIndex()
  
  Description copied from interface: ChannelBuffer
  
  Marks the current readerIndex in this buffer. You can reposition the current readerIndex to the marked readerIndex by calling ChannelBuffer.resetReaderIndex(). The initial value of the marked readerIndex is 0.
  
  Specified by:
  
  markReaderIndex in interface ChannelBuffer
  
  Overrides:
  
  markReaderIndex in class AbstractChannelBuffer
- resetReaderIndex
  
  public void resetReaderIndex()
  
  Description copied from interface: ChannelBuffer
  
  Repositions the current readerIndex to the marked readerIndex in this buffer.
  
  Specified by:
  
  resetReaderIndex in interface ChannelBuffer
  
  Overrides:
  
  resetReaderIndex in class AbstractChannelBuffer
- markWriterIndex
  
  public void markWriterIndex()
  
  Description copied from interface: ChannelBuffer
  
  Marks the current writerIndex in this buffer. You can reposition the current writerIndex to the marked writerIndex by calling ChannelBuffer.resetWriterIndex(). The initial value of the marked writerIndex is 0.
  
  Specified by:
  
  markWriterIndex in interface ChannelBuffer
  
  Overrides:
  
  markWriterIndex in class AbstractChannelBuffer
- resetWriterIndex
  
  public void resetWriterIndex()
  
  Description copied from interface: ChannelBuffer
  
  Repositions the current writerIndex to the marked writerIndex in this buffer.
  
  Specified by:
  
  resetWriterIndex in interface ChannelBuffer
  
  Overrides:
  
  resetWriterIndex in class AbstractChannelBuffer
- discardReadBytes
  
  public void discardReadBytes()
  
  Description copied from interface: ChannelBuffer
  
  Discards the bytes between the 0th index and readerIndex. It moves the bytes between readerIndex and writerIndex to the 0th index, and sets readerIndex and writerIndex to 0 and oldWriterIndex - oldReaderIndex respectively.
  Please refer to the class documentation for more detailed explanation.
  
  Specified by:
  
  discardReadBytes in interface ChannelBuffer
  
  Overrides:
  
  discardReadBytes in class AbstractChannelBuffer
- readBytes
  
  public ChannelBuffer readBytes(int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to a newly created buffer starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length). The returned buffer's readerIndex and writerIndex are 0 and length respectively.
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
  
  Parameters:
  
  length - the number of bytes to transfer
  
  Returns:
  
  the newly created buffer which contains the transferred bytes
- readSlice
  
  public ChannelBuffer readSlice(int length)
  
  Description copied from interface: ChannelBuffer
  
  Returns a new slice of this buffer's sub-region starting at the current readerIndex and increases the readerIndex by the size of the new slice (= length).
  
  Specified by:
  
  readSlice in interface ChannelBuffer
  
  Overrides:
  
  readSlice in class AbstractChannelBuffer
  
  Parameters:
  
  length - the size of the new slice
  
  Returns:
  
  the newly created slice
- readBytes
  
  public void readBytes(byte[] dst, int dstIndex, int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
  
  Parameters:
  
  dstIndex - the first index of the destination
  
  length - the number of bytes to transfer
- readBytes
  
  public void readBytes(byte[] dst)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= dst.length).
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
- readBytes
  
  public void readBytes(ChannelBuffer dst)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination becomes non-writable, and increases the readerIndex by the number of the transferred bytes. This method is basically same with ChannelBuffer.readBytes(ChannelBuffer, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes while ChannelBuffer.readBytes(ChannelBuffer, int, int) does not.
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
- readBytes
  
  public void readBytes(ChannelBuffer dst, int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length). This method is basically same with ChannelBuffer.readBytes(ChannelBuffer, int, int), except that this method increases the writerIndex of the destination by the number of the transferred bytes (= length) while ChannelBuffer.readBytes(ChannelBuffer, int, int) does not.
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
- readBytes
  
  public void readBytes(ChannelBuffer dst, int dstIndex, int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified destination starting at the current readerIndex and increases the readerIndex by the number of the transferred bytes (= length).
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
  
  Parameters:
  
  dstIndex - the first index of the destination
  
  length - the number of bytes to transfer
- readBytes
  
  public void readBytes(ByteBuffer dst)
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified destination starting at the current readerIndex until the destination's position reaches its limit, and increases the readerIndex by the number of the transferred bytes.
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
- readBytes
  
  public int readBytes(GatheringByteChannel out, int length) throws IOException
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified stream starting at the current readerIndex.
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
  
  Parameters:
  
  length - the maximum number of bytes to transfer
  
  Returns:
  
  the actual number of bytes written out to the specified channel
  
  Throws:
  
  IOException - if the specified channel threw an exception during I/O
- readBytes
  
  public void readBytes(OutputStream out, int length) throws IOException
  
  Description copied from interface: ChannelBuffer
  
  Transfers this buffer's data to the specified stream starting at the current readerIndex.
  
  Specified by:
  
  readBytes in interface ChannelBuffer
  
  Overrides:
  
  readBytes in class AbstractChannelBuffer
  
  Parameters:
  
  length - the number of bytes to transfer
  
  Throws:
  
  IOException - if the specified stream threw an exception during I/O
- skipBytes
  
  public void skipBytes(int length)
  
  Description copied from interface: ChannelBuffer
  
  Increases the current readerIndex by the specified length in this buffer.
  
  Specified by:
  
  skipBytes in interface ChannelBuffer
  
  Overrides:
  
  skipBytes in class AbstractChannelBuffer
- writeBytes
  
  public void writeBytes(byte[] src, int srcIndex, int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers the specified source array's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
  
  Specified by:
  
  writeBytes in interface ChannelBuffer
  
  Overrides:
  
  writeBytes in class AbstractChannelBuffer
  
  Parameters:
  
  srcIndex - the first index of the source
  
  length - the number of bytes to transfer
- writeBytes
  
  public void writeBytes(ChannelBuffer src, int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length). This method is basically same with ChannelBuffer.writeBytes(ChannelBuffer, int, int), except that this method increases the readerIndex of the source buffer by the number of the transferred bytes (= length) while ChannelBuffer.writeBytes(ChannelBuffer, int, int) does not.
  
  Specified by:
  
  writeBytes in interface ChannelBuffer
  
  Overrides:
  
  writeBytes in class AbstractChannelBuffer
  
  Parameters:
  
  length - the number of bytes to transfer
- writeBytes
  
  public void writeBytes(ChannelBuffer src, int srcIndex, int length)
  
  Description copied from interface: ChannelBuffer
  
  Transfers the specified source buffer's data to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes (= length).
  
  Specified by:
  
  writeBytes in interface ChannelBuffer
  
  Overrides:
  
  writeBytes in class AbstractChannelBuffer
  
  Parameters:
  
  srcIndex - the first index of the source
  
  length - the number of bytes to transfer
- writeBytes
  
  public void writeBytes(ByteBuffer src)
  
  Description copied from interface: ChannelBuffer
  
  Transfers the specified source buffer's data to this buffer starting at the current writerIndex until the source buffer's position reaches its limit, and increases the writerIndex by the number of the transferred bytes.
  
  Specified by:
  
  writeBytes in interface ChannelBuffer
  
  Overrides:
  
  writeBytes in class AbstractChannelBuffer
- writeBytes
  
  public int writeBytes(InputStream in, int length) throws IOException
  
  Description copied from interface: ChannelBuffer
  
  Transfers the content of the specified stream to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.
  
  Specified by:
  
  writeBytes in interface ChannelBuffer
  
  Overrides:
  
  writeBytes in class AbstractChannelBuffer
  
  Parameters:
  
  length - the number of bytes to transfer
  
  Returns:
  
  the actual number of bytes read in from the specified stream
  
  Throws:
  
  IOException - if the specified stream threw an exception during I/O
- writeBytes
  
  public int writeBytes(ScatteringByteChannel in, int length) throws IOException
  
  Description copied from interface: ChannelBuffer
  
  Transfers the content of the specified channel to this buffer starting at the current writerIndex and increases the writerIndex by the number of the transferred bytes.
  
  Specified by:
  
  writeBytes in interface ChannelBuffer
  
  Overrides:
  
  writeBytes in class AbstractChannelBuffer
  
  Parameters:
  
  length - the maximum number of bytes to transfer
  
  Returns:
  
  the actual number of bytes read in from the specified channel
  
  Throws:
  
  IOException - if the specified channel threw an exception during I/O
- writeZero
  
  public void writeZero(int length)
  
  Description copied from interface: ChannelBuffer
  
  Fills this buffer with NUL (0x00) starting at the current writerIndex and increases the writerIndex by the specified length.
  
  Specified by:
  
  writeZero in interface ChannelBuffer
  
  Overrides:
  
  writeZero in class AbstractChannelBuffer
  
  Parameters:
  
  length - the number of NULs to write to the buffer
- checkWritableBytes
  
  private void checkWritableBytes(int length)
  
  Throws an IndexOutOfBoundsException the length is not 0.
- checkReadableBytes
  
  protected void checkReadableBytes(int length)
  
  Throws an IndexOutOfBoundsException the length is not 0.
  
  Overrides:
  
  checkReadableBytes in class AbstractChannelBuffer

Class EmptyChannelBuffer

Field Summary

Fields inherited from class org.jboss.netty.buffer.HeapChannelBuffer

Constructor Summary

Method Summary

Methods inherited from class org.jboss.netty.buffer.BigEndianHeapChannelBuffer

Methods inherited from class org.jboss.netty.buffer.HeapChannelBuffer

Methods inherited from class org.jboss.netty.buffer.AbstractChannelBuffer

Methods inherited from class java.lang.Object

Field Details

BUFFER

Constructor Details

EmptyChannelBuffer

Method Details

clear

readerIndex

writerIndex

setIndex

markReaderIndex

resetReaderIndex

markWriterIndex

resetWriterIndex

discardReadBytes

readBytes

readSlice

readBytes

readBytes

readBytes

readBytes

readBytes

readBytes

readBytes

readBytes

skipBytes

writeBytes

writeBytes

writeBytes

writeBytes

writeBytes

writeBytes

writeZero

checkWritableBytes

checkReadableBytes